Yeah, I think for smaller communities it'll still be useful to have the full member list available - it's quick enough to find people when there's only a few hundred accounts - but I can see the merit in disabling it for larger boards - especially as you can use the sidebar search to drill-down to find individuals.
I don't think, with twenty thousand plus accounts, it serves much purpose on CycleChat anymore (it'll take half a day or more to scroll through the alphabetical list) so it'll probably be more interesting for the regulars to see the tabbed totals like it is here on XF now.